1. Field of the Invention
The present invention relates to in vivo or in vitro monitoring of a biochemical species. It finds particular application in the monitoring of glucose in diabetics, lactate monitoring for those undergoing physical exercise and heart monitoring for those suffering from heart conditions, oxygen monitoring, and the like, and will be described with particular reference thereto. It will be appreciated, however, that the invention has a variety of other applications, both for clinical monitoring and for research purposes.
2. Discussion of the Art
There are numerous applications for in vivo monitoring of biochemical species, both in humans and in other animals. For example, accurate and precise glucose monitoring is desirable to achieve and maintain predictable and safe glucose levels via insulin administration, diet, and/or other factors. Other applications include lactate monitoring, which could be important in monitoring physical exercise, such as in those participating in professional sports and competitions, and in controlling the heartbeats of patients suffering from different heart conditions with pacemakers, defibrillators, etc. Further examples include oxygen monitoring for a number of conditions and pH monitoring when diabetes and other types of acidosis are potential threats. Yet another example is the monitoring of the extracellular level of a drug administered to a patient.
Currently available technologies for such in vivo monitoring involve the introduction of a probe device through the skin into the subcutaneous layer, or into the dermis of a patient to a selected site. The probe is physically connected, typically by electrical wires or other media to a main control outside the patient's body.
The physical connection allows the acquisition of data from the probe and may also be used for its control. Such systems tend to introduce technical inefficiencies and safety concerns that have often resulted in poor usage compliance by the patient and inaccuracies in the monitoring process. For example, the introduction of the probe into the skin sometimes causes acute and, occasionally, chronic pain. There is also the potential for infection at the site or at the insertion point. Further, there is a potential for the sensing elements, which sometimes contain hazardous or toxic materials, electrical wiring, or other parts of the probe device to break or to degrade within the patient. This may result, for example, from natural movements of the patient or from external forces. This raises further safety concerns including the introduction of hazardous or toxic materials to the body and the potential for electric shocks. These problems contribute to a psychological barrier to the use of currently available probes. To limit the likelihood of such problems arising, the probe and its associated wiring are removed from the skin at frequent intervals, typically every few days, and a new site identified. A new or existing probe is then introduced.
The present invention provides a new and improved probe for in vivo monitoring which overcomes the above-referenced problems, and others.